An autobiography rather than biography, but still an interesting read: The Seven Storey Mountain by Thomas Merton, a cloistered Cistercian monk who was drawn to Buddhist teachings, Zen in particular, and dared write about it.

Merton has been an ecumenical finger pointing at the moon for many. From one of his essays written when reporters were questioning him on his move to a small building away from the main monastery:

"This is not a hermitage, it is a house. (“Who was that hermitage I seen you with last night?”) What I wear is pants. What I do is live. How I pray is breathe. Who said Zen? Wash out your mouth if you said Zen. If you see a meditation going by, shoot it. Who said “Love?” Love is in the movies. The spiritual life is something that people worry about when they are so busy with something else they think they ought to be spiritual. Spiritual life is guilt. Up here in the woods is seen the New Testament: that is to say, the wind comes through the trees and you breathe it."
-From his essay Day of a Stranger.

“In Louisville, at the corner of Fourth and Walnut, in the center of the shopping district, I was suddenly overwhelmed with the realization that I loved all these people, that they were mine and I theirs, that we could not be alien to one another even though we were total strangers. It was like waking from a dream of separateness, of spurious self-isolation in a special world. . . .
This sense of liberation from an illusory difference was such a relief and such a joy to me that I almost laughed out loud. . . As if the sorrows and stupidities of the human condition could overwhelm me, now that I realize what we all are. And if only everybody could realize this! But it cannot be explained. There is no way of telling people that they are all walking around shining like the sun."
- From Conjectures of a Guilty Bystander